The Malignant Melanoma Clinical Cooperative Group consists of four institutions having a long-term goal of decreasing the morbidity and mortality of malignant melanoma, and of gaining new insights into the nature of primary tumor formation and development. In the two year feasibility period it is planned to establish a uniform clinical and pathological approach to the diagnosis of malignant melanoma, and to evaluate clinical tests as aids in the diagnosis of malignant melanoma, and to prove that cooperative approach is feasible in the study of malignant melanoma. Efforts will also be made to detect individuals who are a high risk for the development of primary malignant melanoma based on their pigment forming capacity.